Book/Report

FZJ-2019-04550

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Ballistische Tieftemperatur-Josephson-Kontakte auf der Basis hochbeweglicher zweidimensionaler Elektronengase

Neurohr, K. (Corresponding author)FZJ*

1998
Forschungszentrum Jülich, Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/22646

Report No.: Juel-3607

Abstract: During this thesis ballistic low-temperature Josephson-contactes based on niobium-twodimensional electron gas (2DEG)-niobium structures were designed and fabricated. In order to analyse the influence of the sample preparation on the electronic properties ofthe niobium-semiconductor interface, IV-curves of single interface junctions were measured. We described the results in terms of an extension of the model by Blonder, Tinkham and Klapwijk (BTK). The Josephson-contacts based an an AlGaSb/InAs-heterostructure showed a supercurrent, which was tunable by an additional current injected via an ohmic contact into the 2DEG. The energy dependence of the suppression of a supercurrent by the injected carriers was measured in a four-terminal configuration. By comparing this result with an effective temperature approach a thermalization of the injected carriers could be excluded. In a three-terminal configuration the supercurrent was switched off locally, which was proven by simulating the measured Fraunhofer- patterns. The niobium-InGaAs/InP-niobium samples which also showed supercurrents were examined with respect to phasecoherent transport at finite bias. The observation of fractional Shapiro-steps gave a strong hint to a deviation of the current-phase relation from the sinusodial shape as expected for ballistic Josephson-contacs.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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Database coverage:

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